How UK Wholesale Diamond & Gemstone Buying Actually Works
Hatton Garden, the London Diamond Bourse, and the tax mechanics that make loose stones different from most goods — a practical map, not a legal opinion.
"Wholesale" gets used loosely across the UK gem trade — see Wholesale vs retail: how the gem trade actually prices for how Chaos defines it on this platform. This piece is about the wider UK market mechanics behind that word: where wholesale trading actually happens, and the tax and customs rules specific to loose stones.
Where it happens
Hatton Garden in London remains the UK's historic centre of diamond and gemstone wholesale trading — a concentrated district of dealers, cutters and trade suppliers built up over more than a century. The London Diamond Bourse operates as a member-only trading floor for verified trade professionals, distinct from the open retail shops along the street.
Loose stones sit outside the VAT margin scheme
The VAT margin scheme — which lets a dealer pay VAT only on their profit margin rather than the full sale price — applies to antiques, works of art and secondhand goods, but explicitly excludes loose precious stones. A loose diamond or gemstone bought and resold is VAT-accounted on the full price, not the margin. This is a genuinely non-obvious rule that changes how dealer pricing actually works compared with, say, secondhand jewellery.
Loose stones carry 0% customs duty
Unlike most imported goods, loose (unset) precious and semi-precious stones generally attract 0% customs duty on import into the UK — a rule that materially affects how internationally-sourced stones are priced once they reach a UK dealer, compared with finished jewellery, which doesn't get the same exemption.
The Kimberley Process applies to rough diamonds, not cut ones
The Kimberley Process Certification Scheme — the international system tracking diamonds to prevent conflict-diamond trade — governs rough diamond exports and imports between participating countries. Once a diamond is cut and polished, it moves outside the Kimberley Process's direct certificate requirement, though industry self-regulation (like the System of Warranties) extends similar assurances down the supply chain.
Large cash transactions trigger registration requirements
UK dealers handling cash transactions of €10,000 or more (in a single transaction or linked transactions) fall under High Value Dealer (HVD) anti-money-laundering registration requirements with HMRC — a threshold worth knowing if you're a buyer used to informal cash trading assumptions from other markets.
What this means for a buyer
None of this changes what you should look for in a stone — it explains why UK wholesale pricing structures the way it does, and why a legitimate UK dealer's paperwork looks the way it does. For what to actually check before buying, see How to buy a loose diamond online without getting lost.
Related reading
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Colombian vs Zambian Emerald: Origin, Colour & Price
Colombian carries the historic premium; Zambian often delivers comparable — sometimes better — clarity for less. Neither is the "wrong" choice.
Ruby vs Spinel: How to Tell Them Apart (And Why It Matters)
Two red stones, one long history of confusion — some of the world's most famous "rubies" are actually spinel.
Compare real stones before you commit
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